Charge forming system for port injection internal combustion engine



Jan. 28, 1969 c. F. HIGH 3,424,141

CHARGE FORMING SYSTEM FOR PORT INJECTION INTERNAL I COMBUSTION ENGINE I Filed Aug. 8, 1966 Sheet of 4 FIG. I

INVENTOR CARL F. HIGH ATTORNEYS Jan. 28, 1969 c. F. HIGH CHARGE FORMING SYSTEM FOR PORT INJECTION INTERNAL Sheet COMBUSTION ENGINE Filed Aug. 8, I 1966 mvsmoa CARL a HIGH ATTORNEYS Jan. 28. 1969 c. F. HIGH 7 3,424,141

CHARGE FORMING SYSTEM FOR PORT INJECTION INTERNAL COMBUSTION ENGINE Filed Aug. 8, 1966 Sheet .3 of 4 F|G 3 41 runs- AIM/7- ,Q i-liz/ra?) J 2 AIM/7' a0 4/ --mr Mu; AIM/7 f. FIG. 4

34 A4 INVENTOR CARLEHIGH ATTORNEYS 3,424,141 NAL C. F. HIGH Jan. 28. 1969 CHARGE FORMING SYSTEM FOR PORT INJECTION INTER COMBUSTION ENGINE 7 Filed Aug. 8, 1966 Sheet VENTOR CARL E HIGH ATTORNEYS I I United States Patent 20 Claims ABSTRACT OF THE DISCLOSURE A charge forming system in which the air induction system has a venturi primary air inlet in parallel with a valved auxiliary air inlet, which valve opens by a direct linkage from the main throttle valve of the air induction system in the upper ranges of engine operation and on demand of the engine when same exceeds the capacity of the venturi air inlet. The fuel control has two orifice means in series, the first orifice means consisting of a variable opening controlled by a pin which is actuated from a venturi-vacuum controlled diaphragm with an assist at higher engine speeds from a mechanical linkage connected with the auxiliary air intake valve, and the second orifice means, to which fuel is delivered from the first orifice means, consists of an axially movable piston having longitudinal tapered slots registering respectively with the outlet ports connected to the fuel jet nozzles disposed at each cylinder intake port-runner, the piston being actuated through a direct mechanical linkage with a manifold pressure operated diaphragm.

This invention relates to internal combustion engine control systems, and more particularly to a simplified, integral self-contained control means for a port jet carburetion system operative to provide correct fuel-air mixtures throughout the full range of engine operation, including fuel enrichment means and means inducting air with minimum or no fuel flow to facilitate engine starting.

In modern high performance internal combustion engines, maintenance of proper carburetion, necessary to accommodate variable operating conditions and to eliminate many problems of poor combustion, has resulted in control systems of increasing complexity, instability, and high cost.

An object of the present invention is to simplify and improve fuel-air control systems for internal combustion engines by providing two variable orifice means in series for delivering fuel to intake port fuel jets, as controlled through manifold pressure and mass air-flow sensitive devices and coordinated with air intake valves and a venturi air intake to automatically produce correct fuelair mixtures.

Another object of the invention is to facilitate engine starting with the aforesaid system by providing means supplying sufficient cylinder scavenging air with about onehalf throttle opening and half-opening the first fuel metering orifice when the throttle is fully opened.

A further object of the invention is to facilitate engine idling with the aforesaid system by providing means correctly proportioning fuel and air without any opening of the air-throttle.

Yet another object of the invention is to insure against fuel starvation in a metering system having variable orifices coordinated with air throttle movement by providing an automatic delay in the closing of the upstream orifice on closin the air-throttle to enable the downstream variable chamber to fill with fuel.

Still another object of the invention is to improve fuel metering controls by providing variable fuel orifice means in series with an upstream fuel reservoir and means operice ated by mass air flow to meter fuel from the chamber to the downstream orifice means.

A still further object of the invention is to improve fuel metering in the system of the preceding paragraph by providing means operating the downstream orifice through connections with manifold pressure.

Yet a further object of the invention is to improve variable orifice fuel metering devices by providing an orifice means which acts as its own pump to deliver an excess of fuel for acceleration.

The above and other objects of the invention will become more apparent in the following description, having reference to the accompanying drawings illustrating a preferred embodiment of the invention in which like reference characters refer to like parts throughout the several views and in which FIG. 1 is a fragmentary top plan view of a preferred internal combustion engine embodying the invention and with the air cleaner removed for clarity;

FIG. 2 is a fragmentary cross-sectional view of said engine taken susbtantially on the line 22 of FIG. 1,

FIG. 3 is a fragmentary cross-sectional view of the engine controls taken substantially on the line 33 of FIG. 1,

FIG. 4 is a fragmentary cross-sectional view of the air intake portion of the engine taken substantially on the line 44 of FIG. 1.

FIG. 5 is a fragmentary and diagrammatic view of a control portion of FIG. 3 but with parts in different positions.

FIG. 6 is a fragmentary cross-sectional view of a fuel jet and inlet port runner of the engine taken substantially on the line 66 of FIG. 1, and

FIG. 7 is a fragmentary cross-sectional view taken substantially on the line 7--7 of FIG. 3.

Referring to the drawings in detail, FIGS. 1 and 2 illustrate an engine 10 having an air intake manifold structure 12 provided with two multiple-outlet distributing plenums 14 terminating in cylinder air intake port runners as at 16 (FIG. 6).

The manifold structure 12 is adapted to overlie a cylinder head and crankcase structure (not shown). Adjacent each port runner 16, a vented fuel jet nozzle assembly 18 is mounted to discharge fuel downstream into the air entering the port runner 16. Details of the nozzles have been described in my prior copending patent application Ser. No. 519,132 and are not a part of the present invention except insofar as they are the terminals of the fuel delivery system.

An air intake housing 20, shown in FIGS. 1, 2 and 4, is mounted on top of the air intake manifold structure 12, and comprises a venturi intake branch inlet passage 22 and a supplemental air inlet passage 24, the two passages 22 and 24 arranged in parallel relative to each other and both leading into a throttle passage 26 which is open at its lower end to the central portion of the air intake manifold plenums. A conventional throttle valve 28 is disposed in the throttle passage 26, and mounted on a shaft 30 rotatably carried by the housing 20. FIGS. 3 and 5 illustrate diagrammatically that the throttle shaft 30 has on an exterior end thereof a lever 32, and is urged towards a closed position by an accelerator spring 34. A lever 36, extending in an opposite direction from the lever 32, is adapted for connection with an accelerator pedal (not shown), such that when the accelerator pedal is depressed, the throttle valve 28 will be rotated to an open position as shown in FIG. 3.

An air valve 38 is mounted on a shaft 40 carried by the housing 20 in the supplemental inlet passage 24 as shown in FIGS. 3, 4 and 5. This air valve 38 will normally open automatically under the differential of pressures of atmosphere above the valve 38 and intake air between the air valve 38 and the throttle valve 28, such that as the air demand of the engine increases beyond that which can be supplied through the venturi inlet passage 22 the valve 38 will open automatically to supply the additional required air.

As indicated diagrammatically in FIGS. 3 and 5, the throttle valve 28 has a second lever 42 connected by means of a coil spring 44 to a lever 46 secured to an exterior end of the air valve shaft 40. Normally, when the throttle valve 28 is in its closed position as shown in FIG. 5, the spring 44 will be under some tension keeping the valve 38 closed, or at the A-IDLING position. It will be seen that to ensure this, the spring 34 opposing the opening of the throttle valve 28 must have a greater force in tension than the air valve spring 44. As the throttle valve 28 is moved toward an open position, the first one-half of the opening movement will serve merely to release the tension on the spring 44 but the air valve remains in the A-IDLING position. Thereafter the remainder of the opening of the throttle valve 28 will cause the spring 44, now compressed completely as indicated in FIG. 3, to serve as a solid link between the throttle valve 28 and the air valve 38, moving same to approximately the B-VENTURI LIMIT position shown in dotted lines in FIG. 3. The air valve 38 is, however, still closed in this position. To prevent the spring 44 from buckling when it serves as a solid linkage, a tubular solid element 48 is arranged to be carried within the coils of the spring as shown. Beyond the B-VEN- TURI LIMIT position shown in FIGS. 3, 4 and 5, the air valve can be further opened toward the C-AIR VALVE LIMIT position against the resistance of the spring 44 by differential air pressures as above described which will occur as the venturi inlet passage 22 approaches the limit of the air which it can pass.

A two part fuel control housing assembly 50, as shown in FIGS. 1, 2 and 3, is mounted on the air intake housing 20, and comprises a first housing 52 and a second housing 54. The housing 52 has a fuel chamber 56 connected, as shown diagrammatically in FIG. 2, with a fuel inlet pipe 58 through which fuel is delivered by a pump 60 from a fuel tank 62. The upper part of the chamber 56 is connected through an orifice 63, by any means such as a conduit 64, to the fuel tank 62, for the discharge of vapor back to the tank 62.

The housing 52 has a fuel discharge passage 66 in which is inserted a valve member 68 which has a contoured orifice opening 70 leading from the chamber 56.

The upper part of the housing 52 has a pressure chamber 72 divided by a diaphragm assembly 74, which carries a metering pin 76 extending downwardly through the housing 52 into the contoured orifice opening 70 as shown in FIGS. 2 and 3. The upper portion of the pressure chamber 72 on one side of the diaphragm 74 is connected through an Opening 78 with a conduit or tube 80 seen in FIGS. 1 and 4 with the area of low pressure in the venturi inlet passage 22. Thus, as the throttle valve 28 is opened, air flow through the venturi inlet passage 22 increases, causing a depression in pressure behind the diaphragm 74 moving the metering pin 76 toward the larger area portion of the contoured orifice opening 70, producing an increased flow of fuel from the chamber 56 into the passage 66.

Positions A, B and C indicated in FIG. 3 are the positions taken by the diaphragm corresponding to positions of the air valve previously described. In position A, the throttle is closed. From A to B, the throttle is open and venturi suction can move the diaphragm. From B to C, the diaphragm and pin 76 are moved mechanically from the air valve 38 as follows:

A bell crank 82 is rotatably carried on a pin 84 mounted in the housing 52 and has one end adapted for engagement beneath the diaphragm assembly 74 as shown in FIG. 3, and the other end adapted for engagement with the end of a push rod 86 which extends through a tube 88 into a chamber 90 of the housing 20. The other end of the push rod 86 is attached to a lever 92 connected to the shaft 40 0f the air valve 38. This latter connection is made by the end of the push rod 86 being threaded as at 94 into a cylinder element 96 rotatably carried by the lever 92. Thus the push rod 86 can be adjusted as to length.

It will be seen that opening motion of the air valve 38 by differential air power after spring 44 tension is released will move the push rod 86 against the bell crank 82 causing the other end thereof to move upwardly into engagement with the diaphragm 74, depending on its venturi sensed position. As the air valve 38 is opened beyond this engaging point, it will move the diaphragm 74 against the compression of a spring 98 to further raise the pin 76 and increase the effective area of the orifice 70.

The housing 54 has a cylindrical chamber 100 having one end open to the fuel passage 66 leading from the orifice 70, and the other end open to a control chamber 102 in the housing 20. A piston 104 is closely fitted in and axially movable in the chamber 100, as indicated in FIGS. 2 and 3, and has one end thereof extending outwardly into the chamber 102 and connected by linkage elements 106 and 108 to a diaphragm assembly 110 which forms one side of the wall of the chamber 102. The chamber 102 openingly communicates with the air space intermediate the throttle valve 28 and the inlet passages 22 and 24. The other side of the diaphragm assembly 110 is openly connected by means of a passage 112 with the throttle passage 26 downstream of the throttle valve 28, The diaphragm 110 thus senses and is moved by changes in air intake manifold pressure. The link 108 is fulcrummed at one end on a pin 114, engaging therewith by means of a slot 116, in such a way that the pin 114 may be adjusted within the slot 116 to provide adjustment of the fulcrum point. The link 108 is connected at an intermediate point by means of a pin 118 to the diaphragm assembly 110 as shown in FIG. 2, and the other end of the link 108 is connected by means of a pin 120 to the intermediate link 106 connected to the piston 104.

As seen in FIGS. 2, 3 and 7, the piston 104 has a central passage 122 opening at one end to the inner end of the chamber 100 communicating with the passage 66, and opening through ports 124 to an annulus 125 which feeds the large ends of a plurality of annularly spaced tapered grooves 126 which register with a plurality of annularly spaced fuel distributing orifices 128. The orifices 128 are adapted for connection by means such as conduits 130 to the fuel jet nozzles 18, as shown in FIG. 1.

The movement of the diaphragm assembly 110 will be communicated to the piston 104 which shifts axially to vary the effective openings of the orifices 128 as they are registered with various effective areas of the grooves 126.

A spring 132 urges the diaphragm assembly 110 toward a position where the orifices 128 are fully open. As manifold pressure decreases, the piston 104 will be moved outwardly to decrease the effective area of the orifices 128 and decrease fuel discharge to the fuel jet nozzles 18.

It will be seen that in the above arrangement of the control, there are in effect two variable orifice means in series, the first orifice means being that formed between the metering pin 76 and the contoured orifice opening 70, and the second orifice means being a plurality of distributing orifices 128 variably opened and closed by the tapered grooves 126 of the piston 104. It will also be apparent that the first orifice means (hereinafter called orifice 70), is variably operated in relation to the mass air-flow of the engine, since it is operated both by the diaphragm 74 which is responsive to pressures in the venturi 22 dependent on air flow therethrough, and to the movement of the air valve 38, which is also responsive to air flow either as adjusted by the linkage movement with the throttle valve 28 or as automatically conditioned by the opening of the air valve 38 when the venturi 22 is unable to supply the air demands of the engine. The sec- 0nd orifice means (hereinafter called orifice 128), is variably responsive to variations in manifold pressure of the engine, since the piston 104 determining the effective area of the orifice 128 smoothly follows an intake manifold pressure curve.

At engine idling speed, the minimum fuel flow required is provided by having the orifice 70 very slightly opened, and the second orifice 128 being positioned such that the two orifices in series give the correct pressure drop to supply the fuel to the nozzles 18 for normal idling. With the throttle valve 28 closed, air for idling may be provided through an adjustable air inlet valve 134, indicated in FIGS. 2 and 4, located below the throttle valve 28. If, for any reason, idling speed starts to decrease the intake manifold pressure will correspondingly increase, causing a movement of the diaphragm assembly 110 and consequently of the piston 104 to increase the area of the second orifice 128. As the first and the second orifices are in series, increasing the area of the second orifice is, in effect, the same as increasing the total pressure across the first orifice, and increased fuel metering will result. With the increased flow of fuel through the two orifices in the new position, speed lost by leanness will immediately be restored and the manifold pressure is restored to the initial value.

As the throttle valve 28 is slightly opened as at tip-in, to slightly increase the idling speed, the second orifice 128 will again increase its effective area responsive to the decline of intake manifold pressure. Under tip-in conditions, however, the air inducted through the throat of the venturi 22 will begin evacuation of the diaphragm chamber 72 above the diaphragm 74, and the metering rod 76 will begin withdrawing from the orifice opening 70, thereby increasing the effective area of this first orifice. To aid the feeble evacuation at the tip-in point, the diaphragm assembly 74 is made from plastic and light metal, and the spring 98 is formed with a free length slightly less than the space provided for it. The total absence of spring load at the tip-in position makes it easier for the diaphragm 74, under the feeble vacuum, to lift the metering rod 76, and thus increase fuel fiow to burn with the extra air which is then being inducted by the engine.

When the air throttle 28 is moved more than half open, the air valve spring 44, with its internal stiffening tube 48, has all of its tension removed and begins to serve as a solid link to move the lever 46 and hence the air valve 38 and the lever 92 to operate the bell crank 82 through the push rod 86, to engage the bell crank 82 with the diaphragm assembly 74 and aid the vacuum thereon, to thereby move the metering rod 76 outwardly of the orifice opening 70, which has its walls so contoured that it will meter fuel along a desired fuel curve so as to burn properly with the air which is simultaneously being inducted by the engine through the venturi 22, but with the air valve 38 still closed between positions A and B.

' The metering rod 76 extends through a dash-pot chamber 134 formed in the housing 52. A snap ring type of washer 136 is secured to the metering pin 76 and disposed in the dash-pot 134 which communicates with the chamber 56 and hence is filled with fuel. Although the outside diameter of the snap ring washer 136 is less than the inside diameter of the bore of the dash-pot 134, the movement of the snap ring Washer 136 through the fuel in the dash-pot 134 causes a resistance which retards movement of the metering pin 76 from immediately closing the orifice 70 when the air throttle valve 28 is suddenly closed. This will permit the inner end of the chamber 100 and the passage 66 between the two orifices tobe kept filled with fuel as the volume of the chamber 100 is increased by the retraction of the piston 104 when it is moved by the suddenly decreased manifold pressure. With this chamber between the two orifices always filled, during acceleration the volume therein will be decreased, which puts the fuel between the orifices under increased pressure, which increases fuel delivery and thus aids in acceleration.

It will be noted that the chamber 72 is vented through the tube 88 and the chamber 90, which is open to atmosphere within the air filters (not shown) but is covered by a flame retarding screen member 138, so that vapors which might otherwise tend to collect in the chamber 72 can be withdrawn readily by the induction of the engine or through the vapor return conduit 64 to the fuel tank 62. Shown in FIG. 4 is a tubular member which is a crankcase ventilating tube and forms no part of the present invention.

It will be seen that in the concept of the present invention, a system is provided which is, in effect, a pair of variable orifices in series, operated respectively in response to variations of mass air flow and manifold pressure which are sensed at the venturi air inlet and at the manifold, and transmitted through various mechanical devices to the two series orifice valve means, along with the air intake system which includes not only the venturi but a supplemental air valve initially positioned with throttle movement and opened further with air pressure, the air valve being also connected with one of the orifices. This provides a simplified and rugged control for the port jet carburetion system, including fuel enriching means, means for inducting air with minimum or no fuel to facilitate engine starting, with an integral self-contained means producing correct fuel-toair mixtures for the engine throughout its full range speed and load.

Although I have described only one embodiment of my invention, it will be apparent to one skilled in the art to which the invention pertains that various changes and modifications may be made therein without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. In an internal combustion engine having an air induction manifold including cylinder intake port runners, a throttle valve upstream of said manifold, an intake means upstream of said throttle valve and including in parallel a venturi air inlet and a separate air valve automatically opening to provide additional air over venturi capacity, and means metering fuel into said cylinder intake port runners; a control means comprising (a) said fuel metering means having in series a first and a second variable area orifice means, fuel from said first orifice means being delivered only to said second orifice means, and fuel from said second orifice means being delivered only to said port runners,

(b) means responsive to engine mass air flow operably varying the effective area of said first orifice means, and

(c) means responsive to engine manifold pressure operably varying the effective area of said second orifice means.

2. In an internal combustion engine having an air induction manifold including cylinder intake port runners, a throttle valve upstream of said manifold, an intake means upstream of said throttle valve and including in parallel a venturi air inlet and a separate air valve automatically opening to provide additional air over venturi capacity, and means metering fuel into said cylinder intake port runners; a control means comprising (a) said fuel metering means having in series a first and a second variable area orifice means, fuel from said first orifice means being delivered only to said second orifice means, and fuel from said second orifice means being delivered only to said port runners,

(b) means responsive to engine mass air fiow operably varying the effective area of said first orifice means,

(0) means responsive to engine manifold pressure operably varying the effective area of said second orifice means, and

((1) said second orifice means comprising a housing having a fuel inlet, a plurality of outlet orifices adapted for connection to said port runners, and a distributing chamber open to said inlet and said orifices,

a piston element in said chamber and movable to variably and simultaneously open or close said orifices, and

means operably connecting said piston element with said means responsive to engine manifold pressure.

3. The control means as defined in claim 2 and in which (a) said piston has a plurality of parallel longitudinal- 1y tapering grooves registering with said orifices and a passage connecting said grooves with said fuel inlet to said chamber,

(b) said piston being movable axially with respect to said grooves to simultaneously vary the effective area of said grooves registering with said orifices.

4. The control means as defined in claim 2 and in which (a) said piston is movable in said chamber toward and away from one end thereof,

(b) said fuel inlet is open to said one end of said chamber,

(c) said piston being operable when moved toward said one end of said chamber to increase the effective :area of said orifices while simultaneously decreasing the volume of said one end of said chamber whereby to effect a pumping action increasing the rate of fuel delivery through said orifices.

5. The control means as defined in claim 2 and in which (a) said chamber comprises an elongated tube having one open end and a fuel inlet in the opposite end,

(b) said orifices open to the periphery of said tube,

() said piston element fits closely within and is axially movable within said tube, and has longitudinally tapered peripheral grooves variably axially registering with said orifices, and

(d) said piston element has a passage opening to the grooves and the fuel inlet end of said chamber.

6. The control means as defined in claim 5 and in which (a) said means responsive to engine manifold pressure comprises a housing having a chamber and a diaphragm forming one wall thereof, and means openly connecting said chamber with said manifold, and

(b) mechanical linkage connecting the end of said piston at the open end of said tube with said diaphragm.

7. In an internal combustion engine having an air induction manifold including cylinder intake port runners, a throttle valve upstream of said manifold, an intake means upstream of said throttle valve and including in parallel a venturi air inlet and a separate air valve automatically opening to provide additional air over venturi capacity, and means metering fuel into said cylinder intake port runners; a control means comprising (a) said fuel metering means having in series a first and a second variable area orifice means, fuel from said first orifice means being delivered only to said second orifice means, and fuel from said second orifice means being delivered only to said port runners,

(b) means responsive to engine mass air flow operably varying the effective area of said first orifice means,

(c) means responsive to engine manifold pressure op erably varying the effective area of said second orifice means, and

(d) said first orifice means comprising a housing having a longitudinally variable area passage,

a metering pin element having one end extending into said passage and movable to vary the effective cross sectional area of said passage through which fuel is directed to said second orifice means, and

means operably connecting said pin element with said means responsive to engine mass air flow.

8. The control means as defined in claim 7 and in cluding means to dampen movement of said pin element closing said passage only when rapid engine deceleration produces rapid decrease in engine mass air flow.

9. The control means as defined in claim 7 and including means operably connecting said separate valve with said throttle valve and said pin element to mechanically assist said means responsive to mass air flow and hasten movement of said pin element opening said passage when said throttle valve is moved toward full open position upon starting and rapid acceleration.

10. The control means as defined in claim 7 and in which (a) said housing has a chamber and a diaphragm forming one Wall thereof, and means openly connecting said chamber with a point of low pressure in said venturi air inlet,

(b) said metering pin being directly connected with said diaphragm for operation thereby.

11. The control means as defined in claim 8 and including (a) means urging said diaphragm towards a position in which said pin tends to close said fuel passage, and

(b) said urging means being inoperative at its extreme position whereby slight vacuum in said chamber during the tip-in movement of said throttle valve will move the diaphragm unopposed by said urging means.

12. The control means as defined in claim 8 and including (a) a coil spring within said chamber operable to urge said diaphragm outwardly towards a position in which said pin tends to close said fuel passage, and

(b) said spring having a free length slightly less than will urge said diaphragm to its extreme position whereby slight vacuum in said chamber during the tip-in movement of said throttle valve will move the diaphragm unopposed by resistance of said spring.

13. The control means as defined in claim 1 and including means to dampen closing and opening of said first variable area orifice means only when respectively rapid engine deceleration and acceleration produces respectively rapid decrease and increase in engine mass air flow.

14. The control means as defined in claim 11 and in which (a) said variable area orifice means comprises a housing having a fuel passage and carrying a longitudinally movable metering pin variably opening and closing said passage,

(b) a pressure sensitive means connected with said pin to move same longitudinally,

(c) said pin carrying a washer member loosely fitting in said chamber whereby to brake movement of said pin during rapid engine deceleration.

15. In an internal combustion engine having an air induction manifold including cylinder intake port runners, a throttle valve upstream of said manifold, an intake means upstream of said throttle valve and including in parallel a venturi air inlet and a separate air valve automatically opening to provide additional air over venturi capacity, and means metering fuel into said cylinder intake port runners; a control means comprising (a) said fuel metering means having in series a first and a second variable area orifice means,

(b) means responsive to engine mass air flow operably varying the effective area of said first orifice means,

(c) means responsive to engine manifold pressure operably varying the effective area of said second orifice means, and

((1) means operably connecting said separate air valve 9 with said throttle valve and with said first variable area orifice means to mechanically assist said means responsive to mass air flow and open said first orifice means when said throttle valve is moved toward full open upon starting and acceleration.

16. In an internal combustion engine having an air induction manifold including cylinder intake port runners, a throttle valve upstream of said manifold, an intake means upstream of said throttle valve and including in parallel a venturi air inlet and a separate air valve automatically opening to provide additional air over venturi capacity, and means metering fuel into said cylinder intake port runners; a control means comprising (a) said fuel metering means having in series a first and a second variable area orifice means,

(b) means responsive to engine mass air flow operably varying the effective area of said first orifice means,

() means responsive to engine manifold pressure operably varying the effective area of said second orifice means, and

((1) means operably connecting said separate air valve with said throttle valve and operable as direct solid linkage for actuating the air valve between selected closed positions from the throttle valve and operable to permit automatic opening of said air valve under tension independently of said throttle valve.

17. In an internal combustion engine having an air induction manifold including cylinder intake port runners, a throttle valve upstream of said manifold, an intake means upstream of said throttle valve and including in parallel a venturi air inlet and a separate air valve automatically opening to provide additional air over venturi capacity, and means metering fuel into said cylinder intake port runners; a control means comprising (a) said fuel metering means having in series a first and a second variable area orifice means,

(b) means responsive to engine mass air flow operably varying the effective area of said first orifice means,

(c) means responsive to engine manifold pressure operably varying the effective area of said second orifice means, and

(d) a coil spring operably connecting said separate air valve with said throttle valve, said coil spring operable in a fully compressed condition for producing direct solid linkage between said valves and being operable to stretch under tension for retaining said air valve closed when said throttle is less than onehalf open and for automatic opening of said air valve independently of said throttle valve.

18. The control means as defined in claim 17 and including a rigid support element encompassed by said coil spring to prevent bucking thereof in its direct solid linkage function.

19. In an internal combustion engine having an air induction manifold including cylinder intake port runners,

a throttle valve upstream of said manifold, an intake means upstream of said throttle valve and including in parallel a venturi air inlet and a separate air valve automatically opening to provide additional air over venturi capacity,

and means metering fuel into said cylinder intake port runners; a control means comprising (a) said fuel metering means having in series a first and a second variable area orifice means,

(b) means responsive to engine mass air flow operably varying the eifective area of said first orifice means,

(0) means responsive to engine manifold pressure 0perably varying the effective area of said second orifice means,

(d) said means responsive to engine mass air flow comprising a pressure sensitive means operably connected wit said first orifice means,

means transmitting pressures from a low pressure point in said venturi to said pressure sensitive means for increasing the effective area of said first orifice means with through said venturi during the lower partthrottle range of said engine, and

(e) means mechanically linking said separate air valve with said first orifice means and operable on opening of said separate air valve to assist said pressure sensitive means for further increasing the effective area of said first orifice means during the upper part-throttle and full-throttle ranges of said engine when air requirements exceed maximum air-flow provided by the venturi.

20. The control means as defined in claim 19 and in which (a) said pressure sensitive means connected with said first orifice comprises a housing having a chamber and a diaphragm member as one 'wall thereof,

(b) said first orifice means comprises a passage in said housing, a pin variably opening and closing said passage and operably connected with said diaphragm member for actuation thereof,

(c) said linking means comprises a rod axially movably connected at one end to said separate air valve, and a bellcrank pivotally carried by said housing,

(d) one end of said bellcrank is engaged with the other endof said rod for actuation thereby, and the other end of said bellcrank is engaged with said diaphragm member, and v (c) said rod and bellcrank are constructed and arranged to transmit movement from said separate air valve on opening thereof to said diaphragm to move same in a direction to actuate said pin for variably opening said orifice means passage.

References Cited UNITED STATES PATENTS 2,893,711 7/1959 McDufiie 261-69 XR JULIUS E. WEST, Primary Examinen.

US. Cl. X.R.

increased air flow 

